WASHINGTON — Attorney General Eric Holder has directed the full resources of the Justice Department be deployed to investigate the bombs that exploded at the Boston Marathon.

A department official said Holder has spoken with FBI Director Robert Mueller and with Carmen Ortiz, the U.S. attorney for Massachusetts. The official said Ortiz’s office was co-ordinating the department’s response with the FBI and other federal, state and local law enforcement authorities.

The official spoke on condition of anonymity because she was not authorized to speak on the record.

Two bombs exploded near the marathon’s finish line on Monday, killing two people and injuring many others. A senior U.S. intelligence official said two other explosive devices were found nearby. A third explosion followed at the JFK Library in Boston.